Default timout of 30secs for ConfigRetriever

Default timout of 5sec for use by Transporter (ports etc).

And Ndb_cluster_connection::set_timeout() api for setting timeout from
NDBAPI applications. Should be called before connect. e.g.

c.set_timeout(4200);
c.connect();

Index: ndb-work/storage/ndb/include/mgmcommon/ConfigRetriever.hpp
===================================================================


storage/ndb/include/mgmcommon/ConfigRetriever.hpp:
  WL#3704 mgmapi timeouts: update NDBAPI usage of mgmapi for timeouts
storage/ndb/include/ndbapi/ndb_cluster_connection.hpp:
  WL#3704 mgmapi timeouts: update NDBAPI usage of mgmapi for timeouts
storage/ndb/src/common/mgmcommon/ConfigRetriever.cpp:
  WL#3704 mgmapi timeouts: update NDBAPI usage of mgmapi for timeouts
storage/ndb/src/common/transporter/TransporterRegistry.cpp:
  WL#3704 mgmapi timeouts: update NDBAPI usage of mgmapi for timeouts
storage/ndb/src/ndbapi/ndb_cluster_connection.cpp:
  WL#3704 mgmapi timeouts: update NDBAPI usage of mgmapi for timeouts